November 25, 2008

Galactic Molecule Could Point To Signs Of Alien Life

An organic sugar molecule that is directly linked to the origin of life has been located in a relatively hospitable part of the galaxy, scientists said.

Glyceraldehyde is a molecule with significant ties to the origins of life, as it can react to form ribose, a key constituent of the nucleic acid RNA.

"This is an important discovery as it is the first time glycolaldehyde, a basic sugar, has been detected towards a star-forming region where planets that could potentially harbor life may exist," said Dr. Serena Viti, one of the paper's authors from University College London.

The finding could be a positive step in the search for alien life, as a wide spread of the molecule improves the chances of it existing along side other molecules vital to life and in regions where Earth-like planets may exist.

Glycolaldehyde was first discovered toward the galactic center in 2000. However, the extreme conditions there made scientists unsure as to whether the molecule could form in the rest of the galaxy.

In order to find a more definitive answer, Maria Teresa Beltran of the University of Barcelona and colleagues trained the Plateau de Bure array of radio telescopes on a large star-forming region called G31.41+031, about 26,000 light years away.

The region, known as a hot molecular core, is dense with newly formed stars. The team found several radio and microwave signatures of the presence of glycolaldehyde inside the radio emission from the core.

When those spectral signatures were compared with those from a computer model of how the molecules form on tiny grains of interstellar dust, the data suggested the glycolaldehyde is a few hundred thousand years old.

The study's co-author, Claudio Codella of the Institute of Radio Astronomy in Florence, Italy, said the importance of the discovery lies in the fact that the glycolaldehyde has been detected towards a region where planets orbiting newly formed stars are expected to exist - and planets could be the cradle of life.

"The discovery of an organic sugar molecule in a star forming region of space is very exciting and will provide incredibly useful information in our search for alien life," said Professor Keith Mason, Chief Executive of the Science and Technology Facilities Council.

Further research is needed to look for complex molecules that up to now have only been seen in the galactic center.

"The search for prebiotic molecules in star-forming regions is still in the fledgling stages but the door is open now," says co-author Roberto Neri, an astronomer at the Institute for Millimeter Radio Astronomy, home to the Plateau de Bure facility.

"I believe that many more of these molecules will show up in the near future," he adds.

The discovery, partly funded by the UK's Science and Technology Facilities Council is published in the Astrophysical Journal Letters.